Trajectories of Retention in Opioid Agonist Therapy and Overdose Risk During a Community-Wide Overdose Epidemic in a Canadian Setting

"I'm on the Right Path": Exploring 1-Month Retention in a Homeless-Tailored Outpatient-Based Opioid Treatment Program

BACKGROUND

Homeless-tailored office-based opioid treatment (OBOT) programs have been developed to address the ongoing opioid overdose crisis, which disproportionately affects people experiencing homelessness. The objective of this study was to evaluate the facilitators of and barriers to retention in a homeless-tailored OBOT program.

METHODS

We performed in-depth qualitative interviews with 24 homeless-experienced adults who newly enrolled in Boston Health Care for the Homeless Program's OBOT program from January 6, 2022 through January 5, 2023. We purposively sampled participants based on whether they were retained at 1 month (n = 12) or not (n = 12). We used an abductive analytic process, applying codes to the interview transcripts from an a priori analytic framework based on the Behavioral Model for Vulnerable Populations and supplementing with emergent codes as needed. We compared themes by participants' 1-month retention status to explore facilitators of and barriers to retention in OBOT care.

RESULTS

The average age was 41.9 years, 29.2% were female, 20.8% were Black, 58.3% were White, and 33.0% were Hispanic. Facilitators of retention common to many participants included the clinic experience, low-threshold model, clinic staff, and provision of comprehensive care. Among participants who were retained at 1-month, personal motivation, use of extended-release buprenorphine, and adequate buprenorphine efficacy were additional facilitators. Barriers to retention common to many participants included the clinic's surrounding environment, competing subsistence difficulties, and transportation difficulty. Among participants who were not retained at 1-month, opioid use severity, drug use in social networks, and inadequate buprenorphine efficacy represented additional barriers.

CONCLUSIONS

We identified several common determinants of OBOT retention among our homeless-experienced participants as well as some facilitators and barriers that differed by 1-month retention status. These divergent factors represent potential points of intervention to promote retention in homeless-tailored OBOT programs.

An economic evaluation of community pharmacy-dispensed naloxone in Canada

Aims

To determine the cost-effectiveness of pharmacy-based intranasal (IN) and intramuscular (IM) naloxone distribution in Canada.

Methods

We developed a state-transition model for pharmacy-based naloxone distribution, every 3 years, to illicit, prescription, opioid-agonist therapy and nonopioid use populations compared to no naloxone distribution. We used a monthly cycle length, lifetime horizon and a Canadian provincial Ministry of Health perspective. Transition probabilities, cost and utility data were retrieved from the literature. Costs (2020) and quality-adjusted life years (QALY) were discounted 1.5% annually. Microsimulation, 1-way and probabilistic sensitivity analyses were conducted.

Results

Distribution of naloxone to all Canadians compared to no distribution prevented 151 additional overdose deaths per 10,000 persons, with an incremental cost-effectiveness ratio (ICER) of $50,984 per QALY for IM naloxone and an ICER of $126,060 per QALY for IN naloxone. Distribution of any naloxone to only illicit opioid users was the most cost-effective. One-way sensitivity analysis showed that survival rates for illicit opioid users were most influenced by the availability of either emergency medical services or naloxone.

Conclusion

Distribution of IM and IN naloxone to all Canadians every 3 years is likely cost-effective at a willingness-to-pay threshold of $140,000 Canadian dollars/QALY (~3 × gross domestic product from the World Health Organization). Distribution to people who use illicit opioids was most cost-effective and prevented the most deaths. This is important, as more overdose deaths could be prevented through nationwide public funding of IN naloxone kits through pharmacies, since individuals report a preference for IN naloxone and these formulations are easier to use, save lives and are cost-effective. Can Pharm J (Ott) 2024;157:xx-xx.

The Association Between Self-Reported Anxiety and Retention in Opioid Agonist Therapy: Findings From a Canadian Pragmatic Trial

BACKGROUND

Prescription-type opioid use disorder (POUD) is often accompanied by comorbid anxiety, yet the impact of anxiety on retention in opioid agonist therapy (OAT) is unclear. Therefore, this study investigated whether baseline anxiety severity affects retention in OAT and whether this effect differs by OAT type (methadone maintenance therapy (MMT) vs. buprenorphine/naloxone (BNX)).

METHODS

This secondary analysis used data from a pan-Canadian randomized trial comparing flexible take-home dosing BNX and standard supervised MMT for 24 weeks. The study included 268 adults with POUD. Baseline anxiety was assessed using the Beck Anxiety Inventory (BAI), with BAI ≥ 16 indicating moderate-to-severe anxiety. The primary outcomes were retention in assigned and any OAT at week 24. In addition, the impact of anxiety severity on retention was examined, and assigned OAT was considered an effect modifier.

RESULTS

Of the participants, 176 (65%) reported moderate-to-severe baseline anxiety. In adjusted analyses, there was no significant difference in retention between those with BAI ≥ 16 and those with BAI < 16 assigned (29% vs. 28%; odds ratio (OR) = 2.03, 95% confidence interval (CI) = 0.94-4.40; P = 0.07) or any OAT (35% vs. 34%; OR = 1.57, 95% CI = 0.77-3.21; P = 0.21). In addition, there was no significant effect modification by OAT type for retention in assigned (P = 0.41) or any OAT (P = 0.71). In adjusted analyses, greater retention in treatment was associated with BNX (vs. MMT), male gender identity (vs. female, transgender, or other), enrolment in the Quebec study site (vs. other sites), and absence of a positive urine drug screen for stimulants at baseline.

CONCLUSIONS

Baseline anxiety severity did not significantly impact retention in OAT for adults with POUD, and there was no significant effect modification by OAT type. However, the overall retention rates were low, highlighting the need to develop new strategies to minimize the risk of attrition from treatment.

CLINICAL TRIAL REGISTRATION

This study was registered in ClinicalTrials.gov (NCT03033732).

Implications of Cannabis Legalization on Substance-Related Benefits and Harms for People Who Use Opioids: A Canadian Perspective

In 2018, Canada enacted the Cannabis Act, becoming only the second country (after Uruguay) to legalize the recreational consumption of cannabis. Although there is ongoing global disagreement on the risk-benefit profile of cannabis with increasing legalization in many parts of the world, the evidence of rising cannabis use prevalence postlegalization has been consistent. In contrast, postlegalization changes in various cannabis-related metrics have been inconsistent in Canada and other parts of the world. Furthermore, the implications of cannabis legalization on substance-related harms and benefits for people who use unregulated drugs, particularly opioids, remain unclear. Finally, although Canada did not legalize cannabis to address the opioid crisis, there is rising scientific and popular interest in the therapeutic potential of cannabis to mitigate opioid-related harms. This perspective highlights the implications of cannabis legalization on substance-related benefits and harms for people who use opioids, the current state of Canadian research, and suggestions for future directions.

Outpatient Rapid Titration of Slow Release Oral Morphine for the Treatment of Opioid Use Disorder in a Canadian Setting: A Case Series

INTRODUCTION

In the midst of unprecedented opioid overdose deaths, opioid agonist therapy induction strategies that allow for rapid titration to therapeutic doses for individuals at high risk of overdose are needed. Slow release oral morphine (SROM) is an effective treatment for opioid use disorder; however, current guideline-recommended titration strategies require weeks to achieve therapeutic dose for individuals with high opioid tolerance. Individuals may be lost to care or experience overdose due to ongoing use of unregulated opioids during this time. After years of experience titrating SROM doses rapidly in the inpatient setting, we developed a protocol using short-acting morphine (MOS) to allow for rapid SROM titration in the outpatient setting.

CASES

Patients (n = 4) were eligible if they met the criteria for opioid use disorder and had evidence of high opioid tolerance. Patients received supervised MOS doses in the outpatient setting, which were consolidated into a 12-hour extended-release morphine dose (to a maximum of 500 mg) on the evening of the titration. The total titration-day MOS and 12-hour extended-release morphine were summed into the post-titration-day SROM dose, to a maximum of 1000 mg.

DISCUSSION

In the cases described, substantial reductions in unregulated fentanyl use and social gains, such as obtaining housing, employment, and enrollment in inpatient treatment programs, were observed after rapid SROM titration. No overdoses occurred during rapid SROM titration or during SROM treatment. More research is needed to determine the role for rapid SROM titrations as a stabilization option for outpatients.

Opioid agonist therapy switching among individuals with prescription-type opioid use disorder: Secondary analysis of a pragmatic randomized trial

BACKGROUND

Engagement and retention in opioid agonist therapy (OAT) remains a challenge. This study evaluated the impact of initial randomized OAT allocation on subsequent switching among people with prescription-type opioid use disorder (POUD).

METHODS

Secondary analysis of a 24-week Canadian multicenter, pragmatic, randomized trial conducted between 2017 and 2020 comparing flexible take-home buprenorphine/naloxone versus supervised methadone models of care for POUD. We used Cox Proportional Hazards modeling to assess for impact of treatment assignment on time to OAT switching, adjusting for important confounders. For clinical correlates, we analyzed data from baseline questionnaires on demographic, substance use, and health factors as well as urine drug screen.

RESULTS

Of 272 randomized participants, 210 initiated OAT within 14 days per trial protocol, of whom 103 participants were randomized to buprenorphine/naloxone and 107 to methadone. Within 24-week follow-up, 41 (20.5%) of all participants switched OAT with 25 (24.3%, median 27 days, 88.4 per 100 person-years) and 16 participants (15.0%, median 53.5 days, 46.1 per 100 person-years) switching from buprenorphine/naloxone and methadone arms, respectively. In adjusted analysis, allocation to buprenorphine/naloxone was associated with significantly higher risk of switching (aHR = 2.31, 95% CI 1.22 - 4.38).

CONCLUSIONS

OAT switching was common in this sample of individuals with POUD, with individuals randomly allocated to buprenorphine/naloxone being more than twice as likely to switch versus methadone. This may reflect a stepped care approach in OUD management. More research is needed to evaluate overall retention and outcomes with the different observed risks of switching between methadone and buprenorphine/naloxone.

Access to tablet injectable opioid agonist therapy in rural and smaller urban settings in British Columbia, Canada: a qualitative study

BACKGROUND

Rural and smaller urban settings in Canada are disproportionately impacted by the overdose crisis, highlighting the need for novel public health interventions within these jurisdictions. Tablet injectable opioid agonist therapy (TiOAT) programs have been implemented in select rural communities as a means to address drug-related harms. However, little is known about the accessibility of these novel programs. Therefore, we conducted this study to understand the rural context and factors that affected access of TiOAT programs.

METHODS

Between October 2021 to April 2022, individual qualitative semi-structured interviews were conducted with 32 individuals enrolled in a TiOAT program at participating rural and smaller urban sites in British Columbia, Canada. Interview transcripts were coded using NVivo 12 and data were analyzed thematically.

RESULTS

TiOAT access varied considerably. TiOAT delivery in rural settings is complicated due to geographic challenges. Participants who were homeless and staying at a nearby shelter or those in centrally-located supportive housing had minimal issues compared to those living in more affordable housing on the outskirts of town with limited transportation options. Dispensing policies that required daily-witnessed ingestion multiple times daily were challenging for most. Only one site provided evening take-home doses whereas participants at the other site could only resort to the illicit opioid supply to address withdrawal outside of program hours. Participants described the clinics as providing a positive and familial social environment compared to experiences of stigma elsewhere. Medication interruptions did occur when participants were in hospital and custodial settings, leading to withdrawal, program discontinuation, and overdose risk.

CONCLUSIONS

This study highlights the beneficial ways in which health services tailored for people who use drugs can create a stigma-free environment with an emphasis on social bonds. Other factors such as transportation access, dispensing policies, and access in rural hospitals and custodial settings produced unique challenges for rural people who use drugs. Public health authorities in rural and smaller settings should consider these factors when designing, implementing, and scaling up future substance use services, including TiOAT programs.

Opioid agonist treatment improves progression through the HIV cascade of care among people living with HIV who use unregulated opioids

OBJECTIVES

Opioid agonist treatment (OAT) has been shown to improve certain HIV-related treatment measures among people with HIV (PHIV) with opioid use disorder (OUD). However, there is limited data on the impacts of OAT along the whole HIV cascade of care.

DESIGN AND METHODS

Using data from an ongoing cohort of PHIV who use drugs in Vancouver, Canada, we used cumulative link mixed-effects models to estimate the independent effect of OAT on achieving progressive steps in the HIV cascade among participants using unregulated opioids daily, after adjusting for confounders.

RESULTS

Between 2005 and 2017, we recruited 639 PHIV regularly using opioids (median age 42 years, 59% male, 56% White), of whom 70% were on OAT at their baseline visit. Engagement in OAT showed a nonsignificant trend with higher linkage to HIV care (adjusted partial proportional odds ratio [APPO] = 1.75, 95% confidence interval [CI]: 0.83-3.69), and significantly higher cumulative odds of successfully achieving subsequent HIV cascade steps: on ART (APPO = 3.85, 95% CI: 2.33-6.37); adherent to ART (APPO = 3.15, 95% CI: 2.15-4.62); and HIV viral suppression (APPO = 2.18, 95% CI: 1.51-3.14).

CONCLUSIONS

This study found a high level of OAT engagement among PHIV using unregulated opioids and that OAT engagement resulted in significantly increased progression through some of the higher steps of the HIV cascade. While these findings are encouraging, they highlight the need to reach populations off OAT to maximize the clinical and community-level benefits of ART.